Safety electrical outlet apparatus



1959 I W. J. GALLAGHER 2,898,413

SAFETY ELECTRICAL OUTLET APPARATUS Filed Aug. 20,1956 2 Sheets-Sheet 1 ilgi- INVENTOR WILLIAM J. GALLAGHER BY Kathi, mum, qofgkml ATTORNEY Aug. 4, 1959 w. .1. GALLAGHER 2,398,413

SAFETY ELECTRICAL OUTLET APPARATUS Filed Aug. 20. '1956 2 Sheets-Sheet 2 INVENTOR. 7 .WILLIAM J. GALLAGHER ixikm'mmkm hfbg xmk ATTORNEY SAFETY ELECTRICAL QUTLET APPARATUS William J. Gallagher, Malverne, N.Y.

Application August 20, 1956, Serial No. 605,005

15 Claims. (Cl. 200-42) The present invention relates to safety electrical outlet apparatus enabling electrical power to be withdrawn by authorized persons from a circuit, while protecting other persons against accidental shock and preventing other persons from withdrawing power from the outlet. More particularly, the safety electrical outlet apparatus of the present invention enables authorized persons having a co-operating portion of the outlet apparatus to activate or energize the outlet and thus to condition the outlet for the withdrawal of electrical power. Other persons not having such a co-operating portion of the outlet apparatus are protected from energizing the outlet apparatus by accident and are protected from shock. Unauthorized persons are prevented from energizing the outlet apparatus.

Among the many advantages of the various safety electrical outlet apparatus-described herein as illustrative embodiments of my invention are those resulting from the fact that in their normal unactuated condition they have no live conductive elements which can be reached from the outside so as toshock persons accidentally.

The outlet includes an opening or receptacle through which, in operation, a connection is made to the hot side of the line, that is, to the live electrical main. However, in its unactivated condition, the insertion of conductive objects, such as hairpins, nails, wires, screwdrivers, forks, andthe like into this receptacle cannot strike any live parts. The safety outlet apparatus advantageously positively prevents any child from shocking himself by sticking his finger into the receptacle or by inserting metal objects such as are found in the home. Also, the receptacle opening is relatively small and inconspicuous and discourages accidental or mischevious tampering.

The illustrative embodiments of my invention de scribed herein are very well adapted for use in all types of environments and installations both indoors and out, such as in the home, factory, or'in public areas such as streets and parks. In view of the usually more severe operating requirements for installations in outdoor public areas, the embodiments of my invention are being described with particular emphasis on this type of'installation, for example such'as in street lamps. 'Ihese safety outlet apparatus as described enable maintenance crews to withdraw power from a street lamp easily and conveniently while minimizing any risk of shock to them. They protect the public from shock and prevent unauthorized withdrawal of power.

In the maintenance of streets and of the various pipes and conduits under the streets there are many occasions when repair crews require electrical power. These power requirements often are quite large for the operation of heavy maintenance equipment. In most cases'this power is obtained from the main power lines available in the base of the nearest light pole. Itis customary for the crew to make a temporary electrical splice onto the main lines. This splice must usually be made while the lines are live. Any attempt to throw open a master switch 2,898,413 Patented Aug; 4,1959- while the splice is made is likely to shut down many street lights and trafiic lights, causing confusion and serious inconvenience to the public. Thus, it is normal procedure for repair crews to splice onto live wires for' the power required to do a job. This is a nerve-wracking dangerous operation at any time. At night in stormy Weather when power for an emergency repair isrequired,

the hazard'is large in making and later in removing the" temporary splice. When emergency repairs must bernade quickly in order to restore important segments of the service, the men are under pressure in trying to complete the repair job and yet are forced to work with live c011- ductors in making the splice to obtain the powerneeded.

The present invention entirely removes this hazard while enabling the men to obtain'electrical power quickly and very easily.

When safetyoutlet apparatus as described herein is installed, the repair crew can quickly, conveniently and safely obtain power at any time; tion of the outlet is inserted and then a standard energized socket is available for power. Only a'fewseconds are required to obtain power, and complete safety is assured. As illustrated, the socket is includedin the'co operating portion of the outlet, which is inserted into the" receptacle opening and is twisted so as to activate the outlet and thus to complete a circuit to the contacts in-the socket.

inserted into the receptacle, acts to cam a conductive member outwardly or forwardly into engagement with a Thus, advantageously, it is impossible for anyone to' thrust' in or live contact so as to'activate'the' outlet.

depress-a nail orthe like'andactuate'the' socket.

In use, my safety outlet'may conveniently'beinstalledi in the base of street-lamps orthe like fromwhich'a'w thorized personnel may wish to withdraw electrical power at any time for purposes such as street maintenance or maintenance of pipes, cables,- and conduits running under' When suchsafety outlet is available,

the pavement. an authorized'person conveniently inserts the co-operating portion of the outlet through the opening'into the" receptacle. He gives the co-operating portion a twist,

thus camming a contact forward and completing the circuit into the socket in this co-operating portion of the outlet. Thereafter, electrical power is available'for A large electrical load may b'e fed from this apparatus for its capacity and ratingare" use from this socket.

high.

In this specification and in the accompanying drawings are described and shownemb'odiments of my invention and various'modifications' thereof are indicated for pur= poses of illustration in order that others skilled in thew art may fully understand the safety electrical outlet apparatus of my invention and the manner of applying the apparatus in practical use so that they may modify and adapt it in various forms, each as may be best suited to the conditions of a particular electrical installation The various features, objects and aspects of the present inventionwill be more fully understood from a considera-' tion of the following specification in conjunction with- 0 the accompanying two sheets-of drawings, in which:

Figure 1' is an elevational sectional view through a The co-operating por- Moreover, the few live portions of the safety outlet apparatus are entirely enclosed within a rugged Moreover, any opening which is usually drilled in safety electrical outlet installed in a partition, such as in the wall of the base of a light pole and showing the co-operating portion of the outlet partially inserted into the receptacle opening of the outlet;

' Figure 2 is an elevational sectional view corresponding withFigure 1 with some parts shown as partially broken away for purposes of illustration and showing the parts in a different operative relationship. The co-operating portion of the outlet is fully inserted, and the outlet is activated for use;

Figure 3 is a cross sectional view of the outlet apparatus taken along the lines 33 of Figures 1 and 2 looking to the right;

.Figure 4 is a cross sectional view taken along the lines 44 of Figures 1 and 2;

Figure 5 is a cross sectional view of the co-operating portion of the outlet taken along the line 55 of Figure 1 looking to the right;

Figure 6 is an elevational sectional view of another embodiment of the present invention showing the cooperating outlet portion partially inserted; and

Figure 7 is an elevational sectional view shown as partially broken away for purposes of illustration and illustrating the safety outlet apparatus in activated condition for use.

When installed in a typical application, such as in the base of a street lamp, the safety outlet apparatus, generally indicated at 10 in Figure l, is mounted so as to project inwardly away from the wall or partition 12 on which it is mounted. The outlet is mounted near suitable power mains, such as those feeding street lights, and is placed inside of the partition 12 in any convenient manner so as to give protection to the outlet 10. When the partition 12 is metal and is suitably grounded, that is, connected to an electrically neutral return conductor, it advantageously forms the return or grounded side of the circuit, as will be explained in detail further below. When this partition is not suitably grounded, then a ground return conductor 15 is provided when the safety outlet apparatus is installed as indicated by the dotted conductor in Figure l.

The outlet includes two assemblies. There is a front threaded nipple part 14 including an outer facing flange 16. Removably screwed onto the inner or rear end of this nipple 14 is an insulated housing 18, forming the back portion of the safety outlet 10. For most installatrons, a relatively small hole is drilled through the partition 12 and the threaded nipple part 14 is inserted through this hole from the outside surface 22 of the partition 12.

To enable the nipple 14 to be inserted through the hole 20, the insulated housing 18 is readily unscrewed from the nipple, thus temporarily separating the outlet into two portions. The nipple is then fully inserted through the hole 20 from the outside so that the facing flange 16 at the front end of the nipple 14 abuts firmly against the partition. A lock nut 24 is threaded onto the nipple 14 and is screwed up tightly against the inside surface of the partition 12 so as to hold the nipple rigidly in place and thus forms good electrical contact with the partition. When a ground lead 15 is required, it is wrapped around the nipple in front of the lock nut, which is then screwed up tightly against the lead.

The insulated housing 18 is preferably circular in cross section, although a square or other cross sectional form may be used where suitable. I prefer the circular housing form as being more compact. This housing includes an enlarged contact chamber 26 and includes a narrow rectangular throat 28 (see also Figure 3) near the central part of the housing. The front part of the housing has a threaded recess 30 which screws neatly and firmly onto the rear end of the nipple after the nipple is firmly mounted in place in the partition 12 and is locked in place by a lock nut 31. An insulated conductor 32 extending from a fixed cup-shaped contact 34 is connected to, a suitable power main, and the installation is completed. Thereafter, power can be obtained from the safety outlet at any time desired quickly, conveniently and safely.

It is to be noted that one of the advantages of this apparatus is the fact that the mounting hole 20 is relatively small compared with the load capacity and rating of the outlet apparatus. The outside diameter of the nipple 14 is considerably less than that of the housing 18. By providing a conveniently separable connection where the nipple threads into the recess 30, the outlet is readily separated for installation and then reassembled. By utilizing a smaller mounting hole, time is saved during installation.

This cup-shaped contact 34 fits snugly within the chamber 26 and has a cylindrical rim extending rearwardly and a disc-shaped bottom portion which rests against an insulating spacer washer 38 at the front of this chamber adjacent to the throat 28. The conductor 32 is suitably secured to the rim portion of this fixed contact by soldering as shown, or a crimped connection can be used by means of a grommet and rivet.

A slot 38 (see also Figure 4) extends in from one edge of the contact 34 to the center, and a narrower slot 40 extends in from this same edge of the washer 36. A movable contact member 42 includes a circular shank 44 and an enlarged rear head 46 forming a contact area within the chamber 26. As shown most clearly in Figure 4 the circular shank portion of the movable contact member is assembled with the fixed contact 34 and insulating spacer washer 36 by sliding it laterally into the slots 38 and 40. This shank is held in insulated spaced relationship from the edges of the slot 38 by virtue of the confining action of the narrower slot 40 in the washer and by the alignment resulting from the fit between the opening 28 and the contact 42. The insulating washer 36 also prevents the contact 42 from touching the contact 34 when in its rearward position. The head 46 at the rear end of the contact member overlaps the bottom of the fixed contact 34 and is adapted to make a large area of contact therewith when the member 42 is cammed forward, as explained further below.

In order to maintain the outlet normally in inactivated condition, a compression spring 48 thrusts against the inner edge of the facing flange 16 and runs back within the nipple '14 and thrusts against an insulating cap 50. This cap fits over a threaded receptacle 52 at the forward end of the contact member 42. Thus, the movable contact head 46 is normally held spaced away from the bottom of the fixed contact 34. The contact head 46, as shown in Figure I, normally rests back against an insulating disk 54 forming the rear wall of the chamber 26. This disk is held in place by a C-shaped retaining spring clip 56 fitting into an internal groove at the rear of the housing 18. The conductor 32 runs out through a small hole near one edge of this disk as shown in Figures 1 and 2. This threaded receptacle 52 effectively provides a conductive cam surface for camming the member 42 forward so as to engage the movable contact head 46 with the fixed contact 34.

This safety outlet apparatus has the advantage that the receptacle 52 is normally insulated from the contact 34. Inserting any nail or screwdriver, or the like, tends to push the contact member 42 back away from the fixed contact. Thus, there are no exposed live parts which can produce a shock.

When power is to be withdrawn from this safety outlet apparatus, a co-operating portion of the apparatus, generally indicated at 60, is used. This outlet portion 60 includes a conductive activating cam shaft 62 sheathed in an insulating sleeve 64 throughout most of its length and having its exposed end portion threaded to mate with the receptacle 52. Preferably this is a non-standard type, of thread to deter any tampering with the outlet. The portion 60 includes a housing 66 secured to the other end of this shaft, A standard type electrical outlet socket 68, such as one of the .type to receive-a two-pronged plug is held rigidly in a recess at the front of this housing. In operation the shaft 62 is inserted through the small opening in the facing flange 16' until it) reaches the may conveniently be of the same cross section as the portion fitting into the throat. Turning the portion 60 cams the contact head. 46 firmly forward against the contact 34 establishing a circuit from the. receptacle 52 through the insulated shaft 62 and (see Figure 1) through a short lead 70 to one of the contact leaves 72 inside the standard socket 68. This socket may conveniently be a circular one such as is commercially available from Harvey Hubbell, Inc. such as is rated atamperes at 125 volts or 10 amperes at 250 volts.

As the movable contact head abuts firmly up against the contact 34, a contact pin 74iprojecting slightly from the rear of the housing is drawn up firmly against the facing flange 16 (as shown in Figure 2). This action completes a return circuit from the flange 16 through the pin 74 and through a short lead76 to the other contact leaf 78 in the standard socket 68.

Thus, the outlet. apparatus is activated and electrical power is conveniently and safely obtainedfrom the socket 68.

Among the advantages of this apparatus is the fact that the pin 74 scrapes along the surface ofthe facing flange 16 during the last quarter or half turn or so of the shaft 62. This burnishes. the pin 74 and also the flange 16 yielding clean metal-to-metal contact and pro viding an excellent ground return connection for the equipment. The flange 16 in outdoor installations is exposed to weathering and any. tarnish or dirt film is thus automatically scraped away as the outlet is activated;

To provide a strong purchase onthe shaft 62; its outer end is bent over and fits into a transverse hole 80 in the housing 66. Thus, the pin 74 and contact head 46 can be drawn up very tightly and provide good. connectrons.

A metallic rubbing element 82 such. as a'small machine screw has its head projecting from. the opposite side of the rear of the housing'66' to balance the thrust of the pin 74 against the flange 16, as seen in Figure 2.

When the repair job has been completed and power is no longer required, the outlet portion. 60 is quickly unscrewed and removed, automatically leaving the outlet apparatus 10 in inactivated or de-energized condition.

In the illustrative embodiment of my invention shown in Figures 6 and 7 many parts are identical with those shown in Figures 1-5 and have corresponding reference numbers. Certain portions have corresponding functions and have corresponding reference numbers followed by the suifix a.

The movable contact member 42a includes a conduc tive threaded receptacle 52a and an L'-shaped contact 4601 extending from the back surface. A sleeve 82 of insulating material is press fitted over the-outer cylindrical surface of the receptacle 52a andrests againsta flange 84 at the back surface. The outer cylindrical sLuface of the receptacle 52a is knurled to provide a tight grip between the insulating sleeve and receptacle This sleeve 82 slides snugly within the nipple- 14 and insulates the receptacle therefrom.

To prevent rotation of the contact member 42a, a

short key 86 is provided by a wire' bent into a U-shape and having its ends fitting out intoa pair of axially aligned holes in the wall of 'the'nipple. A longitudinal- 8 groove- 88 in the sleeve 82 forms a keyway fitting this key. 84';

A spring 48a normally urges the contact member toward therear of the outlet apparatus 10a so that the flange 84? abuts against an insulating liner which acts as a: stop for the movable contact member. This liner is held in a predetermined aligned position by a projectinglugz92 at its rear edge whichlprojects out into a slot cut. into the back edge of? the nipple. A contact chamber 26a is formed by the interior of'this liner;

A fixed L-shaped contact 34a. overlaps the movable contact 46hr and is secured in fixed position on a base" 94: To-align the contacts, a lug 96 atone edge" of this base-engagesa recess in the liner 90; From" the rear of the contact base 94 extends a terminal screw 98? which fits through a hole in the center. of an insulating. housing which screws onto theback end of the nipple;

During installation the housing 182: isunscrewed and enables the-nipple to fit through a relatively smallmount ing hole 20. Then a lock nut 24' istightened against the-insidesurface of th'esupporting partition; The housing is then screwed back in place and an insulated conductor 32 is connected onto the terminal 98 under a nut 100.

During use, as shown in Figure 7, the movable contact member 42a is cammed forward by screwing a conductive shaft 62 into' the receptacle 52a. contacts 46a and 34a are'pulled into' firm engagement.

In a particular commercially successful outlet apparatus as shown in Figures 1-5, the housings 18' and 66 and the cap Stlare all formed from machineableplastic material, such as a laminated phenolic and fiber material. The fixed contact 34, movable contact 42, shaft 62, pin 74, nipple 1'4, and facing. flange 16 are of electrical brass. The flange 16 is bonded' to the nippleby brazing. The spring 48* and the two lock nuts 24 and 31 are steel. The insulating spacer washer'36 and the insulating disk 54 are stiff laminated phenolic insulating material.

In this commercially successful outlet the dimensions are as follows:

From the foregoing it will be understood that the embodiments of the present invention described above are W611 suited to provide the advantages set forth, and since manypossible embodiments may be made of the various features of this invention and as the safety electrical outlet apparatus herein described may be varied in various parts, all without departing from the scope of the invention, it is'to be understood that all matter hereinbefore set forth or shown in the accompanying drawings is to be interpreted as illustrative and'not in a limiting sense and that in certain instances, some of the features of the invention may beused Without a corresponding use of other features, or without departing from the scope of the invention.

I claim:

1. Safety electrical outlet apparatus from which'to of an electrical line, a fixed electrical contact arranged l to be connected to the other side of" the electrical line, a movable member having a contact area adapted to engage saidfixedcontact and having a conductive cam Thus, the

surface thereon in conductive relationship with said contact area, spring means normally urging said contact member in a direction. away from said abutmentsurface to hold said contact area thereof in spaced insulated relationship from said fixed contact, said outlet apparatus providing access past said abutment surface to said cam surface.

2. Safety electrical outlet apparatus as claimed in claim 1 and wherein said means defining the abutment surface is a front facing of the apparatus and is con-.

nected to an electrically neutral return conductor for providing the grounded side of an output circuit.

3. Safety electrical outlet apparatus adapted for supplying electrical power including electrically conductive abutment means defining a first contact surface arranged to be connected toone side of an electrical source, a fixed contact arranged to be connected to the other side of the electrical source, a movable member having a contact area adapted to engage said fixed contact, said movable member having a conductive cam surface thereon in conductive relationship with said contact area, spring means acting upon said movable member and normally urging said contact member in a direction Way from said conductive abutment means, said contact area being on the opposite side of said fixed contact from said conductive abutment means, whereby said spring means normally holds said contact area away from said fixed contact, said outlet apparatus including an access opening to said cam surface, and a co-operating portion of the outlet apparatus including an electrically conductive element adapted to engage said first contact surface and having a conductive cam shaft adapted to project through said access opening into engagement with said cam surface, said cam shaft upon rotation thereof moving said movable member toward said conductive abutment means against the force of said spring means, thereby to bring said contact area against said fixed contact while engaging said conductive element with said first contact surface, and a pair of outlet terminals in said co-operating portion, one of said terminals being connected to said conductive element and the other being connected to said cam shaft.

4. Safety electrical outlet apparatus to supply electrical power to an output circuit, said outlet apparatus including means defining an electrically conductive abutment surface adapted to form an electrical neutral return circuit of an electrical power line, a fixed electrical contact arranged to be connected to the line side of the electrical line, a movable member having a contact area adapted to engage said fixed contact and having a conductive cam surface thereon in conductive relationship with said contact area, spring means normally urging said contact member in a direction away from said abutment surface to hold said contact area of the movable contact member in spaced insulated relationship from said fixed contact, and means providing access past said conductive abutment surface to said cam surface.

5. Safety electrical apparatus as claimed in claim 4 and wherein said cam surface is a threaded receptacle of conductive material mechanically coupled to said movable member and electrically connected to said contact area.

6. Safety electrical outlet apparatus including an electrically conductive abutment element having an opening therethrough, a fixed electrical contact positioned to the rear of said abutment element and arranged to be connected to an electrical line, a movable member having a contact area behind said fixed contact and adapted to abut against said fixed contact upon movement of said movable member forward toward said abutment element, said movable member having a conductive cam surface thereon electrically connected to said contact area, spring means normally urging said movable member back away from said abutment elesaid abutment element and (forming a second circuit connection thereto.

7. Safety electrical outlet apparatus including an electrically conductive facing element having an opening therethrough, a fixed electrical contact arranged to be connected to an electrical line, a movable member having a contact area adapted to abut against said fixed contact upon movement of said movable member toward said facing element, said movable member having a threaded receptacle thereon electrically connected to said contact area, spring means normally urging said movable member away from said facing element, and a co-operating portion of the outlet apparatus having a conductive shaft extending in through said opening in spaced insulated relation with said facing element, said shaft having a threaded end mating with said receptacle and drawing said contact area forward against said fixed contact and overcoming said spring means to hold said contact area abutting against said fixed contact, said shaft thus forming a first circuit connection to said fixed contact, and said co-operating portion of the outlet apparatus including a conductive protrusion engaging said facing element and forming a second circuit connection thereto.

8. Safety electrical outlet apparatus adapted to supply electrical power to a load connected therewith, said outlet apparatus including means defining a casing having an exposed conductive surface therein near the front and arranged to be connected to one side of an electrical line, a fixed electrical contact within said casing arranged to be connected to the other side of an electrical line, a movable member within said casing having a contact area normally farther from said conductive surface and adapted to move forward to engage said fixed contact, said movable member having a conductive cam surface thereon in conductive relationship with said contact area, spring means normally urging said contact member back in a direction away from said conductive surface to hold said contact area thereof back away from said fixed contact out of electrical contact therewith, said conductive surface having an opening therethrough giving access to said cam surface.

9. Safety electrical outlet apparatus as claimed in claim 8 and wherein said spring means is a helical compression spring within said casing having its axis aligned with said opening and said cam surface and access to said cam surface is provided through said spring.

10. Safety electrical outlet apparatus adapted to supply electrical power to an external circuit, said outlet apparatus including a tubular casing having front and rear ends and including a conductive facing surrounding a mouth at the front end thereof adapted to be connected to one side of an electrical'supply, said outlet apparatus including a substantially enclosed insulated contact chamber near the rear end, a fixed contact in said contact chamber adapted to be connected to the other side of the electrical supply, a movable member extending forward from said contact chamber and having a contact area behind said fixed contact, a conductive cam surface near the forward end of said movable member electrically coupled to said contact area, a helical compression spring within said casing extending back from said mouth and urging said movable member back away from said mouth and normally holding said contact area spaced behind said fixed contact and insulated therefrom, and a co-operating portion of the outlet apparatus including an electrically conductive element connected to one side of an external circuit and adatped to engage said conductive facing and including an elongated conductive cam shaft connected to the other side of an external circuit and adapted to extend back beyond said mouth into engagement with said cam surface, said cam shaft upon rotation thereof urging said member forward against the action of the spring so as to bring said contact area up against said fixed contact, thereby to place said cam shaft in electrically conductive relationship with said fixed contact.

11. Safety electrical outlet apparatus for providing electrical power including a threaded nipple having front and rear ends and having a flange near the front end thereof and insulating means at the rear end thereof defining a contact chamber, a fixed contact within said chamber adapted to have an electrical conductor connected thereto, a movable contact within said chamber behind said fixed contact, a movable member forward of said fixed contact and supporting said movable contact, said movable member being movable in a direction parallel with the axis of said nipple, fixed means engaging said movable member to prevent its rotation an electrically conductive threaded receptacle on said movable member electrically connected to said movable contact and a helical compression spring within said nipple urging said movable member back away from said flange.

12. Safety electrical outlet apparatus including a threaded nipple having front and rear ends and having a flange near the front end thereof and insulating means at the rear end thereof defining a contact chamber, a fixed contact within said chamber, a movable contact within said chamber behind said fixed contact, a movable member forward of said fixed contact and supporting said movable contact, said fixed contact being L-shaped and including a first leg extending rearwardly and a second leg extending transversely in said contact chamber and said movable contact being L-shaped and including a first leg extending forward to said movable member and a second leg extending transversely in said contact chamber behind the transverse leg of said fixed contact, an electrically conductive threaded receptacle on said 10 movable member electrically connected to said movable contact, and a helical compression spring within said nipple urging said movable member back away from said flange.

13. Safety electrical outlet apparatus as claimed in claim 11 and wherein said fixed contact has a relatively large surface area and has an opening near the center thereof and said movable contact has a shank extending back through said opening and has a contact head thereon overlapping the surface of said fixed contact around said opening.

14. Safety electrical outlet apparatus including a threaded nipple having front and rear ends andhaving a flange near the front end thereof, an insulating housing removably secured to the rear end of said nipple and having a contact chamber therein and a narrower throat forward of said contact chamber, a member fitting in said throat and slidable therein, said throat and member being inter-engaged to prevent rotation of said member, a threaded receptacle at the front end of said member, a first electrical contact at the rear end of said movable member extending back into said contact chamber and electrically connected to said receptacle, and a second contact in said chamber infront of and overlapping said first contact and adapted to have an electrical conductor secured thereto, a helical compression spring within said nipple and insulated from said receptacle and urging said movable member back to hold said contacts apart.

15. Safety electrical outlet apparatus as claimed in claim 14 and wherein said first contact has an enlarged head within said chamber.

References Cited in the file of this patent UNITED STATES PATENTS 513,949 Munson Jan. 30, 1894 1,464,979 Farmer Aug. 14, 1923 1,753,873 Sullivan Apr. 18, 1930 1,846,782 Ballamos Feb. 23, 1932 1,969,345 Andrews Aug. 7, 1934 2,061,460 Freysinger et a1 Nov. 17, 1936 2,255,336 Seghers Sept. 9, 1941 2,405,881 Frei Aug. 13, 1946 

